Decoding the Icelandic sedimentary record of Northern Hemisphere Glaciation

Overview

The Tjörnes sequence is the thickest sedimentary succession exposed onshore Iceland (c. 875 m). Its high sedimentation rate, fossil and biomarker content, accessibility and position in the North Atlantic near the Arctic Polar Front make it an internationally important record of the global cooling since late Miocene time that led to the modern bi-polar glaciation. Among the important environmental changes recorded by the Tjörnes sequence are: the faunal exchange event that marks initial opening of the Bering Strait, which established a Pacific-Arctic-Atlantic oceanic connection; the mid Piacenzian Warm Period, a potential analogue for our future climate; and the onset of Icelandic lowland glaciation that signals intensification of the Northern Hemisphere Glaciation (iNHG). Since 2018 we have been working to update the age model for the Tjörnes sequence and integrate it with nearby marine core-based records. Our partially revised age model already has significant outcomes (Hall et al., 2022): we supported the hypothesis that the mid-Piacenzian Warm Period is not recorded in the lower part of the Tjörnes sequence; we disproved the hypothesis that Atlantic-to-Pacific faunal exchange occurred 2 million years before Pacific-to-Atlantic faunal exchange after the Bering Strait oceanic gateway opened; and we disproved the hypothesis that establishment of Pacific-Arctic-Atlantic connection directly caused the iNHG. 

In this CENTA project, we aim to re-date the upper part of the Tjörnes sequence that contains the record of glaciation. During the late Miocene, Iceland had only small upland glaciers. The iNHG caused the sudden expansion of ice to cover the lowland and coastal regions including Tjörnes. This onset of lowland glaciation in Iceland is clearly recorded within the Tjörnes sequence as the boundary between the Höskuldsvík Group (cycles of basaltic lavas intercalated with sub-aerial, non-glacial sediments) and the Breiðavík Group (cycles of lavas intercalated with glacial diamictites). The intercalated lavas and sediments offer an excellent opportunity for combined radiometric and magnetostratigraphic dating of the onset of lowland glaciation and the subsequent periodicity of glacial/interglacial cycles. We also aim to revise the biostratigraphy of the entire Tjörnes sequence, with special reference to the dozens of bivalve mollusc shell beds that document onset of Pacific-Arctic-Atlantic oceanic connection.  

Training and skills

Students will be awarded CENTA2 Training Credits (CTCs) for participation in CENTA2-provided and ‘free choice’ external training.  One CTC equates to 1⁄2 day session and students must accrue 100 CTCs across the three years of their PhD.

This project would suit a student with a background in any Earth Science field including (but not limited to) Palaeontology, Physical Geography or Geology.  Through the course of the project we will provide training in skills including fieldwork, labwork for radiometric dating and palaeontological sample preparation, museum skills, virtual outcrop development, composite stratigraphic column development, scientific writing and presenting.  There are also opportunities to develop skills in science communication, public engagement and community organising, including getting involved with other projects in the supervisors' research groups.

Further details

Prospective applicants are positively encouraged to contact Stephen Jones ([Email Address Removed]) or Jonathan Hall ([Email Address Removed]) in advance of applying to ask questions about the project, discuss whether working with us on this project at the University of Birmingham is a good fit for you, or to ask questions about putting together a strong application. We are also happy to put you in contact with current and former students to ask questions about their experiences.  See CENTA web page for information on how to apply and general information.  

If you wish to apply to the project, applications should include:

• A CENTA application form, downloadable from: CENTA application
• A CV with the names of at least two referees (preferably three and who can comment on your academic abilities)
• The application should please completed via: https://sits.bham.ac.uk/lpages/LES068.htm. Please select Apply Now in the PhD Geography and Environmental Science (CENTA) section. Please quote CENTA23_B11 when completing the application form.

For further information on how to apply please visit https://centa.ac.uk/apply/how-to-apply/.